The present invention relates to an instrument that acquires sequences of digital data, performs mathematical operations on the acquired data sequences to synthesize new data sequences and then displays waveform representations of the synthesized data sequences.
Many electronic devices produce digital or analog output signals in response to periodic input signals. To test such a device one may apply a known input signal to the device, acquire the digital or analog output signal and then process the acquired signal to produce a test result characterizing the device. When a device under test produces an output data sequence, a test instrument may store the data sequence in an acquisition memory and then perform one or more calculations on the data sequence to provide the test result. When the device under test produces an analog output signal, one may first digitize the output signal to generate a data sequence representing the output signal and then perform calculations on the data sequence in order to provide a test result.
For example, aforementioned U.S. Pat. No. 4,858,142 describes a system for measuring the effective bits of resolution of an analog-to-digital (A/D) converter within a digitizer. The system tests an A/D converter by applying a sine wave of known frequency as input to the digitizer, obtaining a resulting output data sequence produced by the A/D converter, and then performing calculations on the output data sequence obtained. The system includes a waveform generator for producing a sine wave output signal, a switch for selectively connecting the waveform generator to the digitizer input, and a computer for controlling the switch and for performing calculations on the digitizer output data sequence. The computer accesses an acquisition memory within the digitizer to obtain the data sequence generated by the A/D converter in response to the waveform generator output signal.
What would be useful would be a test system that can provide any of a wide variety of test signals to any type of device under test, that can acquire a data sequence characterizing the output signal of the device under test produced in response to the test signal, and that can perform any of a wide variety of user-selectable calculations on the acquired data sequence so as to produce various test results.